Treatment couches have been used in various medical operations. Some examples of treatment couches are surgery tables, operating tables, dentist chairs, and treatment couches for radiation treatment systems. Some examples of radiation treatment systems are gantry-based radiation treatment system and robot-based linear accelerator system. Treatment couches, in general, may be used to support a patient during these medical operations. Treatment couches may also be used to position a patient into a specific position in a treatment room. For example, a treatment couch may be used to position a patient with respect to a linear accelerator or other radiation sources for both gantry-based and robot-based treatment systems.
Another conventional design of a treatment couch used for medical operations is a reclining chair. It has two portions; a base portion, and a reclining portion. The reclining portion of the reclining chair allows a patient to sit back during a scanning procedure. In one conventional design, the reclining portion and the base portion move together to recline a patient backwards for treatment. In another conventional design, the reclining portion and the base portion may move in a folding and unfolding motion to and from one another. This folding and unfolding motion allows a patient to sit on the chair for patient loading purposes, and then allows the patient to sit back, or recline back for patient treatment purposes. These folding functions, however, do not include any mechanism to physically move the patient towards the head end of the chair or table, or to physically move the patient to a specific position on the table or chair. These conventional designs merely position the patient forwards and backwards with respect to an upright sitting position of the reclining chair.
Another conventional design of a patient positioning system used for medical operations is a treatment couch having a leg rest and a drive mechanism, as illustrated in FIG. 1A. Patient positioning system 100 of FIG. 1A includes treatment couch 101, leg rest 102, drive mechanism 103, and extension mounting area 104. Treatment couch 101 is coupled to leg rest 102, and the drive mechanism 103 is coupled to leg rest 102 and extension mounting area 104. The drive mechanism 103 is coupled to the leg rest 102 by a rail or rack and pinion. The rail or rack is mounted to the side of the treatment couch to accommodate various patient heights. The leg rest 102 of FIG. 1A is positioned at a first position on the treatment couch 101, position 107, which is towards the bottom-end 109 of the treatment couch 101 The first position 107 may be used for loading and/or unloading a patient onto and/or from treatment couch 101. The drive mechanism 103 moves the leg rest 102 in one translational direction, x-direction 106, relative to a head end 105 of the treatment couch 101. The leg rest 102, which supports the lower-half of the patient's body, can be moved up and down with respect to the head end 105 using the drive mechanism 103 to adjust an upper-half of the patient relative to the head end 105 of the treatment couch 101.
One type of drive mechanism is a motorized ball screw drive system 150, which includes two motors, mounted on the back of the treatment couch, such as at off-center lines, as illustrated in FIG. 1C. The dual motorized ball screw drive system 150 of FIG. 1C includes motors 151 and 152, belts 153 and 154, multiple pulleys 155, ball screws 156 and 157, and cars 158 and 159 (e.g., ball screw nuts). The dual motorized ball screw drive system 150 is used to convert rotational motion of the motors 151 and 152 about axis 162(1) and axis 162(2) into linear motion of the leg rest 102 or treatment couch 101 in the x-direction 106. As the motors 151 and 152 rotate, the motors drives the belts 153 on pulleys 155, which in turn rotate the ball screws 156 and 157, which in turn drives the bar screw nuts 158 that are coupled to the leg rest 102 in a linear, translational direction (e.g., 106) along rail slides 160, which in turn drives the leg rest 102 in a linear, translational direction (e.g., 106).
The patient positioning system 100 may also be used in other positions, such as a horizontal treating position, as illustrated in FIG. 1B. Leg rest 102 of FIG. 1B is positioned at a second position on the treatment couch 101, position 108, which is closer to the head end 105 of the treatment couch 101 than position 107. Position 108 may be used for treating a patient on treatment couch 101. The patient may be loaded onto the treatment couch in position 107, and then, the leg rest 102 may be moved in the translational x-direction 106 up or down (away from or towards the head end 106) to position the patient on the treatment couch to a treating position, position 108. However, in this conventional design, the patient is adjusted after the patient is loaded onto the treatment couch. Adjusting the patient on the treatment couch 101 using the drive mechanism 103 and leg rest 102 along the seat back of the treatment couch 101 may cause discomfort to the patient, such as the skin of the patient catching on the surface due the friction between the upper-half of the patient's body and the treatment couch 101, the skin of the patient burning from being rubbed across the seat back surface, or the skin of the patient getting pinched between the leg rest 102 and the treatment couch 101, as the leg rest moves from one position to another in the x-direction 106. In another embodiment, a sliding member may be coupled to the lower-torso assembly 202 so that it moves with the translational motion of the lower-torso assembly 202 in the longitudinal direction 206. The sliding member may be a thin back piece, and may be used to reduce the friction between the upper-half of the patient's body and the tabletop 201. The sliding member may also be used to prevent the upper-half of the patient's back from directly lying on the tabletop 201 to help prevent the patient from getting pinched between the lower-torso assembly 202 and the tabletop 201 as the leg rest moves from one position to another in the longitudinal direction 206. It should be noted, however, that the lower-torso assembly 202 may be adjusted prior to the loading of the patient on the treatment couch 200. The lower-torso assembly 202 may be positioned to the appropriate height to align the patient's shoulders with the shoulder line 207 before the patient is loaded onto the treatment couch 200. This prevents the patient from experiencing discomfort from the skin of the patient sliding across the surface of the tabletop 201 when the lower-torso assembly 202 is adjusted.
In addition the discomfort to the patient, some components of the treatment couch 101 of FIGS. 1A and 1B are located inside an imaging zone of the patient for certain height positions. Although the rails or rack of the drive mechanism may not be located within the imaging zone of other heights, such as the 1% female height, the components of the drive mechanism may be within the imaging zone of patients of other heights. For example, during treatment of the 99% male, some components, such as the rail or rack, are exposed in the images of the patient, since they are located within the imaging zone of the patient. For example, the imaging zone of a patient may extend from the head to above the lowest point of the rear pelvic area of the patient while the patient is in a sitting position on the leg rest and treatment couch. In effect, the drive mechanism 103 introduces metal in a treatable region of the patient. Even if the rails or racks were made of materials, such as plastic, instead of metal, these components would still appear in the images of the x-rays within that region.
Similarly, even if the treatment couch 101 were to have a radiolucent region that allows the passage of x-rays or other radiation or is entirely invisible in x-ray photographs or under fluoroscopy, some components of the drive mechanism would be disposed inside this radiolucent region, causing these components to appear in the x-ray images of the radiolucent region. As such, the drive mechanism 103 may not be used in an x-ray environment for all heights of patients.
Another conventional design of a patient positioning system used for medical operations is a treatment couch having a base portion and multiple detachable portions, as illustrated in FIG. 1D. Treatment couch 101 of FIG. 1D includes a base portion 171, and the detachable portions 172(1)-(N) (e.g., multiple back-rests) of the treatment couch 101. One detachable portion 172(1), for example, is coupled to the base portion 171 of the treatment couch 101. Each detachable back-rest 172 has a height 174. The detachable portions 172 may be used to adjust a height of the treatment couch 101 to accommodate differing heights of patients. The detachable portions 172 are used to position a head of a patient with respect to a head end 105 of the treatment couch 101 or to adjust an upper-half of a patient relative to a head end 105 of the treatment couch 101.
The treatment couch 101 of FIG. 1D may include a leg rest 102. Leg rest 102 may be detachable, and may have one or more pivot points for one or more articulations. The multiple back-rests of treatment couch 101 may be mounted to the base portion 171 using a tab portion 173 of the back-rest 172 that is inserted into the base portion 171. The tab portion 173 may be used to easily remove the back-rests 172 from the base portion 171, to change the effective height 174 of the treatment couch 101. The multiple back-rests may minimize the range of adjustment necessary for any given patient. One of the multiple back-rests may include a large-sized back-rest to accommodate the ninety-nine percentile male (e.g., 75.6 inches), and another small-sized back-rest to accommodate the, as well as intermediate-sized back rests. The multiple back-rests may be stored on a rack on the wall of a treatment room.
Although the multiple detachable portions 172(1)-(N) may be used to accommodate different heights of patients, the detachable portions need to be a reasonable weight, such as 25 pounds (lbs), to allow an operator to lift the detachable portion from the base portion and to move the detachable portions to and from the rack on the wall of the treatment room. Although materials, such as carbon fiber, could be used to reduce the weight of the detachable portion, the detachable portions still need to support a patient load up to 500 pounds (lbs).
Another conventional design of a patient positioning system used for medical operations is a treatment couch having tabletop and a detachable leg rest, such as the leg rest 102 illustrated in FIGS. 1A-1D. Similar to the detachable portions 172, the datable leg rest needs to be a reasonable weight, such as 25 pounds (lbs) to allow an operator to lift and carry the detachable leg rest. Similarly, materials such as carbon fiber could be used to reduce the weight of the detachable leg rest, but the leg rest still needs to support a patient load up to 500 pounds (lbs). However, in these conventional designs having the leg rest 102, when tipping the treatment couch 101 to allow loading of the patient, such as illustrated in FIG. 1A, the seat pan of the leg rest could only be lowered to approximately 24 inches above the floor. However, the seat pan of the leg rest needs to be about 15-18 inches from the floor to accommodate loading of patients of smaller heights. As such, the leg rest 102 only allowed loading of patients of certain heights using a seat pan height of 24 inches or more.